/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.mapred;
import java.io.IOException;
import org.apache.hadoop.ipc.VersionedProtocol;
/**
* Protocol that a JobClient and the central JobTracker use to communicate. The
* JobClient can use these methods to submit a Job for execution, and learn about
* the current system status.
*/
interface JobSubmissionProtocol extends VersionedProtocol {
/*
*Changing the versionID to 2L since the getTaskCompletionEvents method has
*changed.
*Changed to 4 since killTask(String,boolean) is added
*Version 4: added jobtracker state to ClusterStatus
*Version 5: max_tasks in ClusterStatus is replaced by
* max_map_tasks and max_reduce_tasks for HADOOP-1274
* Version 6: change the counters representation for HADOOP-2248
* Version 7: added getAllJobs for HADOOP-2487
* Version 8: change {job|task}id's to use corresponding objects rather that strings.
* Version 9: change the counter representation for HADOOP-1915
* Version 10: added getSystemDir for HADOOP-3135
* Version 11: changed JobProfile to include the queue name for HADOOP-3698
* Version 12: Added getCleanupTaskReports and
* cleanupProgress to JobStatus as part of HADOOP-3150
* Version 13: Added getJobQueueInfos and getJobQueueInfo(queue name)
* and getAllJobs(queue) as a part of HADOOP-3930
* Version 14: Added setPriority for HADOOP-4124
* Version 15: Added KILLED status to JobStatus as part of HADOOP-3924
* Version 16: Added getSetupTaskReports and
* setupProgress to JobStatus as part of HADOOP-4261
* Version 17: getClusterStatus returns the amount of memory used by
* the server. HADOOP-4435
* Version 18: Added blacklisted trackers to the ClusterStatus
* for HADOOP-4305
* Version 19: Modified TaskReport to have TIP status and modified the
* method getClusterStatus() to take a boolean argument
* for HADOOP-4807
* Version 20: Modified ClusterStatus to have the tasktracker expiry
* interval for HADOOP-4939
*/
public static final long versionID = 20L;
/**
* Allocate a name for the job.
* @return a unique job name for submitting jobs.
* @throws IOException
*/
public JobID getNewJobId() throws IOException;
/**
* Submit a Job for execution. Returns the latest profile for
* that job.
* The job files should be submitted in <b>system-dir</b>/<b>jobName</b>.
*/
public JobStatus submitJob(JobID jobName) throws IOException;
/**
* Get the current status of the cluster
* @param detailed if true then report tracker names as well
* @return summary of the state of the cluster
*/
public ClusterStatus getClusterStatus(boolean detailed) throws IOException;
/**
* Kill the indicated job
*/
public void killJob(JobID jobid) throws IOException;
/**
* Set the priority of the specified job
* @param jobid ID of the job
* @param priority Priority to be set for the job
*/
public void setJobPriority(JobID jobid, String priority)
throws IOException;
/**
* Kill indicated task attempt.
* @param taskId the id of the task to kill.
* @param shouldFail if true the task is failed and added to failed tasks list, otherwise
* it is just killed, w/o affecting job failure status.
*/
public boolean killTask(TaskAttemptID taskId, boolean shouldFail) throws IOException;
/**
* Grab a handle to a job that is already known to the JobTracker.
* @return Profile of the job, or null if not found.
*/
public JobProfile getJobProfile(JobID jobid) throws IOException;
/**
* Grab a handle to a job that is already known to the JobTracker.
* @return Status of the job, or null if not found.
*/
public JobStatus getJobStatus(JobID jobid) throws IOException;
/**
* Grab the current job counters
*/
public Counters getJobCounters(JobID jobid) throws IOException;
/**
* Grab a bunch of info on the map tasks that make up the job
*/
public TaskReport[] getMapTaskReports(JobID jobid) throws IOException;
/**
* Grab a bunch of info on the reduce tasks that make up the job
*/
public TaskReport[] getReduceTaskReports(JobID jobid) throws IOException;
/**
* Grab a bunch of info on the cleanup tasks that make up the job
*/
public TaskReport[] getCleanupTaskReports(JobID jobid) throws IOException;
/**
* Grab a bunch of info on the setup tasks that make up the job
*/
public TaskReport[] getSetupTaskReports(JobID jobid) throws IOException;
/**
* A MapReduce system always operates on a single filesystem. This
* function returns the fs name. ('local' if the localfs; 'addr:port'
* if dfs). The client can then copy files into the right locations
* prior to submitting the job.
*/
public String getFilesystemName() throws IOException;
/**
* Get the jobs that are not completed and not failed
* @return array of JobStatus for the running/to-be-run
* jobs.
*/
public JobStatus[] jobsToComplete() throws IOException;
/**
* Get all the jobs submitted.
* @return array of JobStatus for the submitted jobs
*/
public JobStatus[] getAllJobs() throws IOException;
/**
* Get task completion events for the jobid, starting from fromEventId.
* Returns empty aray if no events are available.
* @param jobid job id
* @param fromEventId event id to start from.
* @param maxEvents the max number of events we want to look at
* @return array of task completion events.
* @throws IOException
*/
public TaskCompletionEvent[] getTaskCompletionEvents(JobID jobid
, int fromEventId, int maxEvents) throws IOException;
/**
* Get the diagnostics for a given task in a given job
* @param taskId the id of the task
* @return an array of the diagnostic messages
*/
public String[] getTaskDiagnostics(TaskAttemptID taskId)
throws IOException;
/**
* Grab the jobtracker system directory path where job-specific files are to be placed.
*
* @return the system directory where job-specific files are to be placed.
*/
public String getSystemDir();
/**
* Gets set of Job Queues associated with the Job Tracker
*
* @return Array of the Job Queue Information Object
* @throws IOException
*/
public JobQueueInfo[] getQueues() throws IOException;
/**
* Gets scheduling information associated with the particular Job queue
*
* @param queue Queue Name
* @return Scheduling Information of the Queue
* @throws IOException
*/
public JobQueueInfo getQueueInfo(String queue) throws IOException;
/**
* Gets all the jobs submitted to the particular Queue
* @param queue Queue name
* @return array of JobStatus for the submitted jobs
* @throws IOException
*/
public JobStatus[] getJobsFromQueue(String queue) throws IOException;
}